An elimination reaction is a type of organic reaction in which a simple molecule; water, for example, is formed from the combination of adjacent carbon atoms of a larger molecule. For example:
E2 Mechanism:
This mechanism was founded by Sir Christopher Ingold. The E2 stands for bimolecular elimination and it is a one step mechanism in which carbon-hydrogen and carbon-halogen bonds break to form a double bond.
As you can see in the diagram above, the hydrogen atom and the hydroxide ion in the ethanol molecule combine to form water by the process of elimination. Since the two carbon atoms have been freed of one of their bonds, a double bond forms between the them, and the result is ethene. Elimination reactions can be considered the opposite of addition reactions. In most organic elimination reactions, a hydrogen atom is lost and a double bond is formed. Because of this, the result of the reaction is usually an alkene.
Here is another example of a simple elimination reaction, in which cyclohexanol is converted to cyclohexene. Water is also produced here.
E1 Mechanism:
The E1 stands for unimolecular elimination and the reaction mechanism has two steps: ionization and deprotonation. The first step of Ionization occurs when the carbon-halogen bond breaks to give a carbocation intermediate. Deprotonation is the removal of a proton from a molecule to form a conjugate base. In this case, the second step would be deprotonation of the carbocation.
Elimination
by Nikki and Jonah
Table of Contents
What is an elimination reaction?
An elimination reaction is a type of organic reaction in which a simple molecule; water, for example, is formed from the combination of adjacent carbon atoms of a larger molecule. For example:
E2 Mechanism:
This mechanism was founded by Sir Christopher Ingold. The E2 stands for bimolecular elimination and it is a one step mechanism in which carbon-hydrogen and carbon-halogen bonds break to form a double bond.As you can see in the diagram above, the hydrogen atom and the hydroxide ion in the ethanol molecule combine to form water by the process of elimination.
Since the two carbon atoms have been freed of one of their bonds, a double bond forms between the them, and the result is ethene. Elimination reactions can be considered the opposite of addition reactions. In most organic elimination reactions, a hydrogen atom is lost and a double bond is formed. Because of this, the result of the reaction is usually an alkene.
Here is another example of a simple elimination reaction, in which cyclohexanol is converted to cyclohexene. Water is also produced here.
E1 Mechanism:
The E1 stands for unimolecular elimination and the reaction mechanism has two steps: ionization and deprotonation. The first step of Ionization occurs when the carbon-halogen bond breaks to give a carbocation intermediate. Deprotonation is the removal of a proton from a molecule to form a conjugate base. In this case, the second step would be deprotonation of the carbocation.
Reaction Mechanism
E1 Demonstration Video
E2 Demonstration Video
Works Cited
http://en.wikipedia.org/wiki/Elimination_reaction#E1_mechanism
http://en.wikipedia.org/wiki/Christopher_Kelk_Ingold
http://en.wikipedia.org/wiki/Deprotonation
http://en.wikipedia.org/wiki/Carbocation
http://en.wikipedia.org/wiki/Ionization